Machine for producing pipes



Ap 17, 945. J. F ER-LA 2 74 086 MACHINE FOR PRQDUCING' PIPES .Fiied Oct. 19, 1939 a Sheets-Sheet 1 P 1711945. J. FER LA I MACfiINE FOR PRODUCING PIPES Fiigd' Oct. 19, 1939 s Sheets-Sheet 2 April 17, 1945. v 3 JFERLA 2,374,086'

MACHINE .F R PRODUCING P Ii=Es Filed Oct. 19. 1959 'a sne ts-snet 3 n i ifa r reey J. FERLA momma FOR rnonucme PiPEs April 17, 1945.

' 7 Filed Oct. 19, 1939 8 Sheets-Sheet 4 April 17, 1945. J I q. FERLA M ',2,374,0s 6

. MACHINE FOR PRODUCING PIPES FiledOct. is, 1939 s Sheets-Sheet s hlllllllllllllllf five/Pia?" ami/2g.

A' rulv, 1945.

J. FERLA r 2,374,086 MACHINE FOR gnonficme PIPES Filed Oct. '19, "1939" a Sheets-Sheet 1 L/IIIIlIII/l/II/ll v 45 April 1945- FECRYLA 2,314,086

1 MACHiNE FOR rnobuc'menrns Fild Oct. 19, 1939 8 Sheets-Sheet 8 frewzezar Patented Apr. 17, 1945 UNITED STATES PATENT v OFFICE I r Foit l 'it fliilcmG PIPES John Ferla, Camden, N. 1., assignor, by direct and mesne assignments, to U, S. Asbestos Cement Pipe Company, Camden, N. .L, a corporation of New Jersey Application October 19, 1939, Serial No. 300,275

' facture of sheeting by first producing a tubular structure, which is slit along one longitudinal edge and developed into fiat form. I

While the invention deals primarily with tubes of asbestos and cement composition, it may utilize other cementitious compositions or be combined with other ingredients, such as infusorial earth, soapstone, talc, silica, hydrates of lime, waterproofing compound, or any other refractory material capable of forming a binder with asbestos and cement.

In the art, it has been known to produce tubes or sheeting, either by a cardboard machine, which-is a complicated apparatus and employs expensive felt conveyors and is wasteful, or by rotary or travelling screens, which also operate in conjunction with felt conveyors; so that the production of tubes or sheeting by these means becomes expensive and, in addition, entails other disadvantages, such as, for instance, that only moderatepressure tubes can be produced, which lack compactness and strength.

' vide tubes with corrugations, with or without bell 7 It is, therefore, one of the main objects of the I present invention to provide for producing sheeting, plain-ended tubes, or tubes with bell collars, which may be inexpensively manufactured, dispensing with the employment of felt conveyors, and which tubes are compact, non-porous, and

of high resistivity and strength.

It is an important object of the invention to provide for producing tubes with bell collars on a mandrel without breakag of the bell collar due to relative circumferential speeds of, different sized portions thereof: This is accomplished by the provision of relatively movable peripheral portions on a roll or cylinder'bearing against the diflerent sized portions ofthe mandrcL liquid pulp, which is utilized to form the basic or initial layer for the tube or sheet material, and

to which additional layers of the same material are caused to adhere 'under compression, and build up to a thickness to suit the particular requirements of the tube or sheeting.

It is a further object of the invention to provide for the productinon of tubes or sheeting as low as /8 of an inch in thickness, up to any commercial dimension.

A still further object of the invention embodies the provision'whereby the composition material is initially prepared substantially of the same consistency as wet clay, and molding said composition material into the required tubular form by continuous longitudinal pressure until th tube is completely formed. v

It is also an object of the invention wherein the composition material is subjected toa preliminary compression, and thereafter to. a final compression.

It is a further object of the invention to procollars. I

It is also an object of the invention to provide for producing tubes in length exceeding those capable of being manufactured by the cardboard or paper machines. It is also an object of the invention to provide for forming tubes or sheeting, which'are capable of being mixed in the process of manufacture with water-proofing compound, so that the tubes or sheeting are inherently waterproof; and, if desired, surface water-proofing may beadded.

-, as those mentioned, will become apparent from a 4 perusal'of the invention, which is set forth in a preferred embodiment, together with modifications thereof, illustrated by more or less diagrammatic views in the accompanying drawings, in

, which:

Fig. 1 is a vertical cross-section, partly in elevation, of an apparatus embodying thi inven- It is a further object of the invention to form the tube from a mixture of composition material, in which the water content and the cement and asbestos content have a definite pre-determined ratio, 0 that the end product in the continuous operation of tubes is always of the same quality and strength. It is'a further object of the invention to pro vide for applying the composition material aaa Fig. 2 is a longitudinal verticalsection on the line 2-2 of Fig. 1;

Fi 3 is an end view or a calender machinef t Fig. 4 is a vertical section therethroush on the line 4-4 of Fig. 3;

Fig. 4a is a fragmentary detailed section of the.

tube and associated rolleriwhen tubes are formed with rough surfaces, which are shown exagger-.

ated;

5 1: an assembly view in side elevation of the entire nothing apparatus;

Numerou other objects, equally as important.

Fig. 6 is a horizontal section therethrough on the line 6-6 of Fig.

Fig. 7 is a similar section on the line 1-! of Fig. 5;

Fig. 8 is an end view of the apparatus shown in Fig. 6;

Fig. 9 is a cross-section on the line 9-9 of Fig.

Fig. 10 is a longitudinal section through a collapsibleshell;

Fi 11 is a cross-section therethrough on the line l|l| of Fig. 10;

Fig. 12 is a view similar to Fig. 11, showing the shell in collapsed condition; I

Fig. 13 is a viewsimilar to Fig. 12, of a. slightly modified form of shell;

Fig. 14 is a view similar to Fig. l of the apparatus for producing corrugated tubes;

Fig.- 140. is a side elevation, partly in section, of a further modified arrangement of the molding screen and calenders, with drives therefor;

Fig. 141) is a diagrammatic end view of the drives thereof;

Fig. 140 is a diagrammatic end view of the screen and rolls;

Fig. 15 is a top plan view of the power driven rotary screen used in the apparatus shown in Fig. 14;

Fig. 16 is a perspective view of a corrugated tube produced thereon;

Fig. 17 is a top plan view of a compression roller for cooperation with a mandrel, shown in Fi 1;

Fig. 17a is a partial sectional view through a calender roll of modified form;

Fig. 18 is a perspective view of a finished tube, provided with a bell collar;

Fig. 19 is a longitudinal section through the mandrel and formed tube, the mandrel having closing discs at both ends; 7

Fig. 20 is a longitudinal section through the power driven rotary molding screen;

Fig. 20a is a partial sectional viewthrough a screen mold of modified form;

collar;

Fig. 23 is a section through an imperforate mandrel, surrounded by a fabric lining intermediate the mandrel and the formed tube;

Fig. 24 is a top plan view of a power driven rotary molding screen, used in conjunction with the roller and mandrel, shown in Figs. 22 and 23;

Fig. 25 is a section through a shell used 'with a mandrel; and v Fig. 26 is an assembly view in section of a modifled form of molding apparatus.

In the manufacture of sheeting or tubes from cementitious composition material, preferably asbestos and cement and/or various other ingredients, it is very important that the mixture of the various ingredients shall havea predetermined fixed ratio, so as to insure a perfect end product.

- It is for this reason that great care has been given to the solution of this problem and the present invention has been evolved with the object in view of obtaining a product of uniform standard quality. which is non-porous, highly resistant and merchantable.

While the invention is particularly described in connection with the manufacture of asbestos and cement tubes, it is, oi course, understood that it is not limited to the particular ingredients mentioned, being applicablegenerally to cementitious having been subjected to considerable treatment so as to remove any crude fibres, to render the same fluff'y without diminishing the length of the fibres and to render the same capable of intimate mixture with other ingredients in dried form, whereupon the mixture is ready to be introduced into a vat which contains water, and subjected to the influence of agitators.

From the mixing vat, the mixture is conducted into a reservoir and thence into tubes l6 which lead to a large vat I! with which the tubes 16 communicate by the outlets l8 and 29.

The vat I1 is filled with a mixture having a maintained liquid level, and is provided with a plurality of agitators 25 and 21, to keep the mixture agitated and in suspension and maintain uniform consistency.

A horizontal shaft 28 extends longitudinally through the vat and is supported in bearings 29 and 30 provided on the outside of the vat and attached thereto.

The shaft 28 carries a spider frame 3! on which is 'mounted a cylindrical screen 32 which'at the right end, as viewed in Fig. 2, is provided with a frusto-conical portion 33, and thence continues into a cylindrical portion 34 of smaller diameter than the body portion of the screen, for a purpose later to be described.

The shaft 28 is provided with a gear 35 to which power is imparted from any suitable source, so that the screen 32 is directly driven and is partly immersed in the mixture contained in the vat l1, and acts as a carrier for bringing the layers of the liquid mixture to a roller or mandrel, generally designated by 35, which is supported on horizontal stub shafts 31, and is formed on the right end as viewed in Fig. 2, with a frusto-conical portion 38, and then with a cylindrical portion 39,

of larger diameter than the body portion of the mandrel. Y

It is obvious thata tube formed on the mandrel will take the same form, at the right end, as the frmto-conical and cylindrical portion of the mandrel, whereby a tube with a so-called bell collar on one end is produced.

The mandrel may be provided with perforations throughout its length while its interior communicates with a pipe 40, which leads to a vacuum pump (not shown) if vacuum be desired for starting the forming operation, but it is not essential. If desired, a strip of fabric may be placed around the mandrel to prevent the suction from drawing the cementitious material into and closing the perforations of the mandrel.

Brain pipes 4| and 42 are provided at. opposite ends of the screen mold 32, and serve to drain therefrom the water which enters the interior of the rotary screen in its operation.

The mandrel 36 is engaged on each side by a I forms a liquid layer on the drel.

' source is imparted.

ment, as described above, is supplied by achute 48, and which hoppers discharge the mixture through a chute 43 onto the roller 43.

In the hopper, an agitator 50 is provided to keep the mixture agitated, and a brush roller near the bottom of the hopper, regulates the rate of discharge.

' A pipe 52, provided with perforations, emits atomized water and sprays the same on top of each roller 43, so as to impart to the dry mixture just sumcient moisture to make the same adhere form a cement aggregate in a In operation, the liquid mixture in the vat l1 periphery of the rotary screen 32 and is transferred thereon onto the mandrel as an initial layer due to the matural adherence. of the wet mixture, enhanced by the suction eifect maintained in the interior of the man- In the continuous rotation of the mandrel, by reason of its frictional engagement with the rotary screen, the. dry mixture, moistened. by the sprays 52, is superposed by the rollers 43 onto the initial layer formed bythe rotary screen; so that,

ina complete revolution of the mandrel, there are formed from one to at least three layers, the

first one being the initial layer produced by the rotary screen; thereafter the second layer of moistened mixture is imparted by the right roller 43, as viewed in Fig. 1; and thereafter the third layer'is produced by the moistened mixture if a greater thickness is desired. This successive application of layers continues until the desired thickness of the pipe is built up, the wet layers supplied by the mold screen 32 alternating with the dry or semi-dry layers applied thereover by the rollers 43.

The moistened layers are compacted with the initial layer by pressure engagement of the rollers" the mandrel and to each other,

4.3, and adhere to and this process is continued until the proper thickness of the tube is built up.

Attention is called to is floatingly mounted so as to engage under gravity the molding screen-in a bearing, which is open at the top, so that the mandrel can be lifted up vertically, as will be hereinafter described.

left roller43, also of the fact that mandrel poses.

' sired or one of high compression,

in the calender machine, and further compacted,

. ipe 10, controlled It is noteworthy that, when the initial layer is formed on the mandrel by vacuum or suction being maintained therein, this aids in causing the initial layer to adhere to the mandrel; but that once the initial layer is formed, it merely acts as an anchoring means for the dry mixture to adhere thereto, and the continued use of the vac- ,uum' is not necessary but may be utilized to some extent to remove the water which is extracted from the layers by the pressure of the rollers 43. As soon as the'tube of the desired thickness is built up, the rotary screen is, of course, brought to a standstill; the mandrel and the tube formed thereon are removed by lifting them out vertically or horizontally, and a new mandrel is put in place for the production of another tube.

After the tube has been built upon the mandrel 36, if a high pressure tube is desired, the mandrel and the tube, as a unit, are lifted out and placed in the calender machine, shown in Figs. 3 and 4. The same comprises a base 53, having bearings 54, in which is journaled a roller 55, provided with a pulley 58', to which power On the base 53 arealso provided standards 51, each equipped with a bushing 58, to receive a threaded spindle 58 which, at'its forward end,

from any suitable:

A pipe 80, leading to be provided.

carries a frame 50, in which one end of a roller BI is. journaled, adapted to contact with one side of the tube, which is still on the mandrel 36. A roller 52, mounted similarly to the roller 6 l is engaging the tube on the other side thereof.

A pipe P is arranged above the tube and is provided with a series of perforations to emit water proofing compound'in atomized state to spray the rollers SI, 62, and the tube T, so that, in addition to. the inherent waterproof character of the tube, by reason of mixing a waterproof compound with the dry mixture, also a surface waterproofing may In operation, the power driven roller 55. causes the tube and the mandrel to rotate, and by friction, rollers GI and 32 are driven, are calender rollers and impart a smooth finish to the surface, and also compact the same further.

.If it is desired to give to the tube a rough surface, then the' rollers are provided with grooves 83 (Fig; 4a) which produce flne ribs 54 on the tube, whereby the same. is providedof greater strength.

It is, of course, to be understood that, when the tube is first formed on the mandrel, it is a roughly finished product and may be used for some pur- However, if a better appearing tube is dethen it is placed pression machine, generally indicated by 55, comprises a casing 66 of the general outline of the tube andthe bell collar, which casing is supported on standards 61 and 68.

The vacuum tube 69 leads to therear end of the chamber formed by the casing, and a'branch by a valve 1 t, leads to the forward end of the casing chamber.

- A pipe 12, provided with a valve and water into the casing, as indicated in Fig. 6.

A hollow piston 14,- of slightly smaller diameter than the chamber, is secured to a piston rod 15, which is hollow and surrounds another piston rod 16, which projects through the piston rod 15, and through the piston 14, and has secured thereto. at its forward end, an auxiliary piston 11, which has a. diameter sufiicient to contact with the walls of the mandrel 35. r

The piston rod 15 enters a casing;1 8 and is connected with a piston '19, which is nnderthe infiuence of pressure fluid admitted into the chamber of the casing 18 behind the piston 19 by a a valve 8|, whence the pipe 82 leads' to the front part of the chamber defined by the casing 18.

The piston rod 16 continueson and enters a casing 83, where it is provided with a piston 84.

Pipes 85 and 86 lead from a valve 81, respectively, to the rear and front'portion of the chamber in the casing 83. A pipe 89, whence a. pipe leads to a source fluid supply (not shown) It is thought unnecessary of the construction of the compression machine as not per se forming apart of the invention and only such parts are referred to which are necessary for an understanding 'of the invention when the mandrel and the tube are forced inwhich latter 13, admits air 88 connects the' valves 8| and 81 and is provided with a-fittin'g of pressure to describethe details abutting relation to the ring Si is inserted, which ring is slightly smaller than the diameter of the chamber to provide an outlet for the passage of water.

In addition, a removable plate 92 is provided in ring, there being a packing ring 93 provided to form a perfect seal.

A door 94 is hingedly connected with the casing, as at 95, and is provided with an opening 96, which is slightly larger than the diameter of the largest portion of the mandrel 35, and the other end of the door is provided with a handle 87 and the tube and of the tervening screen has a, bolt 98, adapted to enter an aperture 99 1 in the casing wall.

When the parts are in the positions shown in Fig. 6, the piston 74 is caused to advance by applying pressure to the piston 19 in the casing 78, which pressure preferably is one thousand pounds per square inch, more or less, and causes longitudinal compression of the tube.

Thereafter the door 94% is opened; the plate 92 removed and replaced by an imperforate large ring (not shown), whereupon the door 9% is closed and the piston ll is caused to advance by permitting pressure to act on the piston 86, which pressure preferably is about one hundred pounds per square inch, more or less.

The advance of the piston ll forces the mandrel 38 through the door opening 95 and is discharged onto a conveyor (not shown), which conveyor is of a form adapted t cradle the mandrel.

Thereafter the piston 7? is returned to its original position. After the ejection of the mandrel, the door so is opened and a collapsible shell, shown in Figs. 10 to 13, is inserted while the door 96 is open and the imperforate filler ring removed.

Thereafter the tube and shell are removed and left lying until ready for use, the shell serving to maintain the form of the tube and facilitate the handling of the material, while in green" condition. The piston it serves to eject the tube.-

As indicated in Figs. 10 to 12, a collapsible shell 166 is slit longitudinally, and is controlled by a crank mechanism, generally designated by ml, which comprises discs m2, mounted on a shaft I021: journaled in bearings ltd on one edge of the split shell. to actuate the crank mechanism lfil.

A link tilt? is secured to each disc E32 and is connected to a bracket lat, secured to the shell on the opposite side of the longitudinal slit.

It is evident that, upon actuation of the handle I03, the mandrel may be expanded into the position shown in Fig. 11 or collapsed into the position shown in 12'.

In Fig. 13 a modification of the crank mechanism for the collamible shell is shown, wherein an additional link it}? is provided, which is attached to a bracket it, also secured to the shell adja. cent a bearing I89, to which is pivoted a link Elli secured tothe disc Hi2. Thus a double throw for the crank is provided, which is useful where small tubes are involved.

Referring again to Fig-6, attention is called to the provision of a blow out opening I I 5, controlled by a valve H2, permitting particles of materials, or any foreign substances, to be blown out by opening the valve 13, so that water may flow between the piston 14 and the casing wall to escape through the opening l I I, carrying along the foreign substances.

Before a mandrel and tube are placed in the The shaft has a handle Hi3 from the The rolls 23? operate compression machine, a cloth wad, saturated with a lubricant, is placed on the piston 11, and the same is reciprocated so that the walls of the casing 66 are properly lubricated for the reception of a tube and mandrel.

In Fig. 14 a view similar to Fig. 1 is shown, depicting the molding of corrugated tubes. Here a cylindrical screen H3 is provided with longitudinal rods H4, spaced circumferentially, which cooperate with longitudinal grooves I is on a man drel H6, so that in the rotation of the screen, the liquid mixture of cementitious material is imparted by both the longitudinal rods and the inportions to the mandrel and, likewise, rollers H7 and H8 are corrugated to cooperate with the surface of the mandrel in producing corrugated tubes.

The corrugated tube HS, stitutes the final product paratus shown in Fig. 14.

The modus operandi of this apparatus is in all respects similar to the straight tube obtained with the apparatus depicted in Fig. 1, and includes the placing of an initial layer, from the liquid mixture, onto the mandrel, and superposing of two layers obtained from the dry mixture stored in hoppers I20, and thereafter moistened on the transfer rolls, and repeating this cycle of operations until a tube of desired thickness is built up. A further modification is shown in Figs, 14a, 14b and 140 in which the screen mold is desigshown in Fig. 16, conobtained with the apnated 232. The screen mold 232 is mounted on a shaft 233 journaled in hearings in standards 2% and 236' capable of vertical adjustment, as indicated in Fig. 14b. The screen mold 232 has bearing thereagainst a transfer calender roll 235 on a shaft 236 also journaled in hearings in the standards 234 and 23%, but capable of horizontalad- J'ustment to accommodate for adjustment of the screen mold 232 to different vertical positions. Mounted above the transfer or calender roll 235 are a pair of calender rolls 23? carried by shafts 238 journaled in hearings in the standards 236 and 23 for adjustment horizontally toward and mandrel adapted to be disposed thereupon the transfer roll 235 (Fig. 140). in a manner similar to the rolls 63, described above (Fig. 1), and apply moist layers of cementitious material to the initial layer on the mandrel applied by the molding screen or transferred thereto by the calender rolls 235.

The molding screen is driven by a gear 239 on the shaft 233, while the calender or transfer roll 235 is driven by a sear 2% on the shaft The gears 239 and 259 are adapted to be connected with a suitable power drive for operation thereby in properly timed relation.

The rolls 28? are driven through a train of gears from a shaft 265, having a driving gear 2&2 thereon at one end, which may be driven from the same power drive that operates the gear 239 and 26a. The opposite end of the shaft Elli carries a pinion 2&3 meshing wtih a gear 2 which gear in turn meshes with idler gears 245, which gears 26d and 265 are journaled on the pedestal 235. Gears 246 are fast on the shaftsiidfl of the rolls 237, and mesh'wi'th idler gears 2G5, being driven between thereby. These gears are adjustable in their.

. modate pipes of diderent diameters or thickness.

In Figs. 1'7 to 25, inclusive, detail views of rollers, mandrels, screens, and tubes to be produced areshown. j

The rollers 43 cooperate with the mandrel 36, which is shown as having series of perforations, and is closed at the ends by discs I2I and I22. Similarly, the cylindrical screen 32 is closed at the ends by discs I23 and I24.

When producing a tube with an integral bell collar, provision should be made for relative circumferential speed of the bell forming portions coacting with the mandrel, either of the calender roll, or the molding screen, as shown in Figs, 17a and a.

To accommodate for this, the roller 43a in Fig. 170 has a sleeve 43b journaled on the reduced end thereof to bear upon the enlarged portion of the mandrel. It is provided also with a collar 43c adjustable thereon to confinethe material.

The molding screen 32a may be provided with -temal circumferential groove I26, in the collar, so

that, upon interfltting of tubes, the groovesalign to receive lead or composition, whereby the tubes.

are joined.

Instead of a collared tube, a straight tube T' may be produced by means of the cylindrical screen I21, the roller I28, and the mandrel I29.

If desired, the mandrel may be imperforate and provided with a fabric lining I30. In this case,

themandrel and tube, when placed on a'vehicle, in view of the presence of the fabric, the mandrel may be removed by hand, as the fabric yields and the mandrel may be removed to insert a-collapsible shell, which retains the shape of the tube. In order to preclude the necessity of providing separate machines for various sizes of tubes, shells I3I may be provided to line the chambers of the compressing machine, s that one machine may be used for producing a number of tubes of various diameters, as will be readily understood.

Referring to Fig. 26, the process described is carried out there with a slight modification. The

liquid mixture is stored in a vat I32, whence it 4 flows onto a travelling screen or endless conveyor I33, which is in engagement with the lower end of the mandrel 36, to impart thereto the initial layer while again the rollers 43, receiving and claim my invention as broadly as the state of the art permits.

I claim:

1. In a machine for forming pipes, the combination with a mandrel, of means for containing a .liquid cementitious composition, means for transferring said liquid composition to the mandrel and forming an initial wet layer of cementitious material on the mandrel, rollers having'bearing engagement with opposite sides of the mandrel,

and means for forming a moistened layer of cementitious material on one of the rollers for transfer thereby onto the initial layer on the mandrel.

2. In a machine for forming pipes, the combination of a mandrel, means for containing a liquid cementitious composition, means for transferring said liquid composition to the mandrel and forming an initial wet layer of cementitious materialon the mandrel, a roller having peripheral bearing engagement wtih the mandrel, means for pressing the roller against the mandrel, and

means for forming a moistened layer of cementitious material on the roller for transfer thereby onto the initial layer on the mandrel.

3. In a machine for producing pipes, the combination with a mandrel, of means for containing a liquid cementitious composition, means for transferring said liquid composition to the mandrel and forming an initial wet layer of cementitious material on the mandrel, a roller having bearing engagement with the mandrel, resilient means pressing the roller against the mandrel, and means for forming a layer of cementitious material on the roller for transfer thereby to the mandrel.

4. In a machine for producing pipes, the combination with a mandrel, 'of means for forming an initial layer of cementitious material on the mandrel, a roller having peripheral bearing engagement with the mandrel, means for moistening the periphery of said roller, and means for applying cementitious inaterial'to the moistened surface of the roller to, form a layer thereon for transfer onto the initial layer on the mandrel.

5. In a machine for producing pipes, the combination with, a mandrel, of means for forming .an initial layer of cementitious material on the mandrel, a roller having peripheral bearing engagement with the mandrel, resilient means pressing the roller against the mandrel, means for moistening the surface of the roller, and means for applying relatively dry cementitious material moistening substantially dry mixture, compact I the tube by connecting a source of vacuum at one or both opposite ends of the cylinder 66. This connection may be made through the pipe III at one end and the pipe 69 at the opposite end, which will facilitate drying of the tube throughout its length; the water passing out of the tube through the perforations in the mandrel.

While the drawings show preferred embodi- ,ments of my improved apparatus, numerous changes and alterations may be made without departing from the spirit of the invention.

I, therefore, do not limit myself to the details onto the moistened surface of the roller to form a layer thereon for transfer onto the initial layer on the mandrel. I

6. In a machine for producing pipes, the combination with a mandrel, of a screen mold adapted to operate in a liquid suspension of cementitious material and in peripheral contact with the mandrel for forming an initial layer thereon, rollers having peripheral bearing engagement with opposite sides -of the mandrel, resilient means acting on the-rollers tending to press the of constructions and arrangement, as shown, but

same toward the mandrelQjmeans for moistening the peripheral surface of each'of the rollers, and means for applying relatively dry cementitiousmaterial to the' moistened surface of each roller to form a layer thereon for transfer onto the initial layer on the mandrel.

7. In a machine for producing pipes, the combination with a mandrel having journal pins on oppositeends thereof, of a screen mold adapted to operate in a liq id suspension of cementitious material to apply an initial layer to the mandrel,

and means forming vertical slots siidably receiv. ing the journal pins therein and mounting the mandrel over the screen mold for pressing engagement against the periphery of the screen mold by gravity pressure, and calender rolls arranged on opposite sides of the mandrel in bearing pressure relation.

8. In a machine for producing pipes, the combination with a mandrel having journal pins on opposite ends thereof, of a vat adapted to contain a liquid suspension of cementitious material, a screen mold operatively mounted in the vat for transferring a layer of cementitious material to the mandrel, and means forming vertical slots slid-ably receiving the journal pins therein and for guiding the mandrel for vertical sliding movement over the screen mold and for bearing pressure engagement with the screen mold by gravity, and calender rolls arranged on opposite sides of the mandrel in bearing pressure relation. a

9. In a machine for producing pipes, the combination with a mandrel having portions of dif= ierent diameters for forming pipes with bell collars', of a screen mold for applying the initial layer of cementitious material onto the mandrel, said screen mold having dilferent sections thereof of difierent diameters complementary with the sections of the mandrel, and means mounting the sections of the screen mold for relative rotation.

10. In apparatus for producing pipes, the com. bination of a rotary screen mold adapted to sup ply cementitious material to a mandrel having portions of different diameters for forming pipes with bell collars, said screen mold having longitudinally arranged screen sections thereof of different diameters constructed for relative movement in cooperation with the mandrel.

11. In apparatus for producing pipes, the combination with a mandrel having portions thereof of different diameters for forming a pipe thereon tious material and to apply a layer thereof onto the mandrel, said screen mold having different longitudinal screen sections thereof constructed of different diameters corresponding with the sections of the mandrel and arranged for relative rotation to each other, and calender rolls on opposite sides of the mandrel in peripheral bearing relation therewith, each of said calender rolls being constructed with longitudinal sections thereof of different diameters complementary to the sections of the mandrel.

13. In apparatus for producing pipes, the combination with a mandrel, of a screen mold adapted to operate in a liquid suspension of cementitious material and to apply the same to the mandrel, means mounting said mandrel over the screen mold with the axis of said mandrel arranged substantially in vertical alignment with the axis of the screen mold, calender rolls arranged on opposite sides of the mandrel and mounted for relative movement toward each other, and means for pressimz the calender rolls inwardly in bearing relation against opposite sides of the mandrel.

14. In apparatus for producing pipes, the cormbination of a rotary drum member arranged substantially in horizontal relation and adapted to receive a mandrel thereover above the axis of the Bil rotary member, calender roll members arranged in spaced relation on opposite sides of the axis of the rotary member and spaced thereabove in position to receive the mandrel therebetween and to bear against opposite sides thereof, means mounting said calender roll members for relative movement toward and from each other, pressure means for pressing the calender roll members substantially in opposed directions to apply pressure against opposite sides of the mandrel, and. means for supplying cementltious material to one of said members for transfer to the mandrel and to form a layer on the mandrel.

15. Apparatus for molding tubes having a bellend from a cementitious composition material, including a vat containing the material in suspension, a rotary screen in said vat filtering out the liquid from said material, a mandrel above said screen and substantially in vertical registry with the screen and arranged in position for transfer of the wet layer adhering to said screen to said mandrel, and means for superposing on the wet layer adhering to said mandrel a layer 16. Apparatus for molding tubes from a fibrous cementitious composition material, including a mandrel before the next succeeding layer is apvat containing the material in suspension, 9. rotary screen with a bell end in said vat filtering out the liquid from said material, a mandrel above said screen and substantially in vertical registry with the screen and arranged in position for transfer of the wet layer adhering to said screen to said mandrel, and means for directly superposing on the Wet layer adhering to said mandrel a layer of moist material under pressure before the next succeeding layer is applied to said mandrel.

17. Apparatus for molding tubes having a cell end from a fibrous cementitious composition material, including a vat containing the material in suspension, a rotary screen with a bell-forming end in said vat filtering out the liquid from said material, a mandrel in position for transfer of the wet layer adhering to said screen onto said mandrel, means for superposing on the wet layer adhering to said mandrel a layer of fibrous cementitious material, and means for compacting the layers on said mandrel before the next succeeding layer is applied from the screen.

18. Apparatus for molding tubes having a bell end from a fibrous cementitlous composition material, including a vat containing the material in suspension, a rotary screen with a bell end in said vat filtering out the liquid from said material, a mandrel in position for transfer of the wet layer adhering to said screen to said mandrel, means for superposlng on the wet layer adhering to said mandrel a layer of moist material, and means for compacting the layers on said plied to the mandrel.

19. Apparatus for molding tubes from a cementltious composiiton material, including a vat containing the material in liquid suspension, a rotary screen in said vat filtering out the liquid from said material, a mandrel above said screen in position for transfer of the wet layer adhering to said screen to said mandrel, and means for superposing on the wet layer adhering .to said mandrel a layer of moist material and including calender rollers cooperating with said mandrel for compacting the layers thereon before the next succeeding layer is applied to the mandrel.

20. In an apparatus for producing pipes having a bell end from a fibrous cementitious material, a vatcontaining said fibrous cementitious fnaterial in suspension, a mold screen having a bellforming end portion and suspended in the vat in position .for transferring a layer of said material fromthe vat to a mandrel, saidmandrel being adapted 'to form a, pipe thereon with a. bell,

of the roller during rotation thereof, and means for applying substantially'dry cementitious material to the wet surface of theroller at a point in the .turning movement thereof intermediate the point of application of liquid and the point of contact with the mandrel.

22. In apparatus for forming pipes, the combinatiofi with a mandrel, of means for containing a liquid suspension of cementitious composition,

means for forming a wet layer from said material and for transferring said layer to the mandrel,

means forming a moistened surface mounted in moving pressure relation against-a side of the mandrel, means for apply ng substantially dry cementitious composition material to saidmois tened surface for transfer thereby onto the mandrel in superposed relation with the wet layer thereon, and means for pressing the moving sur; I

face against the mandrel.

23. In pipe forming apparatus for producing Pipes, a roller member, means ioumaling said roller member for turning movement adapted to receive a coated mandrel thereover, a plurality of horizontally spaced rolls above said flrst-mentioned roller member and arranged to be dis-' posed on opposite sides of thelmandrel and to :be moved in opposed directions toward each other,

and means for applying pressure to said rolls in opposed directions towardthe opposite sides of the mandrel. z v

24. In a machine for-producing pipes, the combination with a mandrel having journal pins on opposite ends thereof, of a roller member beneath the layer from the 'mold. screen onto the mandrel.

the mandrel in position for bearing relation of v the mandrel on the upper side of the roller member, relatively movable calender rolls arranged on opposite sides of the mandrel, pressure means acting to move the calender rolls substantially in opposed directions in pressure bearing relation 1 with opposite sides of the mandrel, means for Supplying cementitious material to the mandrel to build uplayers thereon under the pressure of the calender rolls, and means holding the mandrel' over'the roller member for turning movement and for bodily raising movement relative thereto between the'calendar rol.ls during the building up of layers on the mandrel.

bination of a mandrel, a rotary screen mold arranged Substantially in horizontal relation beneath the mandrel and having the axis thereof approximately parallel with the axis of the mandrel, relatively movable calender rolls arranged in spaced relation on opposite sides of the axis of the mandrel, pressure means acting to move the calender rolls substantially in opposed directions against opposite sides of said mandrel, and means for supplyingcementitious material to the screen mold for transfer therefrom to forma layer on the mandrel.

.26. In a machine for producingp pes, the combination of frame structures spaced apart, a mold I screen journaled in the frame structures at opposite ends thereof, a set of calender rolls spaced apart and disposed above the mold screen in position to receive a mandrel therebetween, a transfer roll super'posedon the mold screen in posi-' tion fortransfer of material from the, mold screen onto the mandrel. between the calen der rolls, means mounting the calender rolls in the frame structures for turning movement and also for relative bodily movement toward and from each other, means for driving the mold screen and transfer roll at one end thereof, and means for driving the calender rolls including a train of gears at the opposite end thereof from.

the first-mentioned driving means and adapted for operative connection with the first-mentioned driving means.

a'mold screen adapted to form a layerof cementitious material, a transfer roll superposed on the mold screen and arranged beneath the calender rolls for transferring the layer from the mold screen onto the mandrel, driving means connected with the mold screen at one end thereof for'operating' said screen, and separate driving means at the opposite end of the calender rolls for driv-t ing saidcalender rolls.

28. In a machine for producing pipes, the combination with a mandrel, of means for containing a liquid cementitious composition, a mold. screen operativel mounted to -form alayer thereon of the composition, a roll having peripheral bearing engagement with the mandrel, means for pressing thercll againstthe'mandrel, means for fo ming a moistened layer of cementitious material on said roll for transfer therebyonto'the mandrel, and ,a transfer roller interposed between the mold screen and the mandrel for transferring 29. P In a machine foriproducing pipes, the com bination with a mandrel, of means for containing a liquid cementitious composition, a mold screenoperatively mounted to forma layer thereon of the composition, a roll having peripheral bearing engagement with the mandrel, means for press- I ing the roll against the mandrel, means for forming a moistened layer of cementitious material on said roll for transfer thereby onto the mandrel, a transfer roller interposed between the; mold screen and the mandrel for transferring the layer from the mold screen onto the mandrel, and

means at respectively opposite ends for driving 4 the pressure roll and the mold screen;

. JOHN WELL 25. In apparatus for-producing pipes, the com-- 27. In apparatus for producing pipes, the com-- bination of a set of'calender rolls spaced apart, and adapted to receive a mandrel therebetween, 

